question on bulkhead connector bypass

yes no doubt. I think what I'm asking is: assuming you are not running more than the engine and some brake and turn signals, how many amps are being drawn when battery needs a charging current? Is it a number related exactly to what is being run (i.e. specific lights, etc) or is it a maybe a more fixed amperage ? Seems like it would not be the max amp output of the alt .but maybe it is.?